Robust decoupling control synthesis

Adaptive decoupling synchronous control of dissimilar redundant actuation system for large civil aircraft

“…The robust optimal control theory was used to solve the coupling problem [24], and the coupling terms between different channels are regarded as disturbance and a synchronous controller based on QFT theory is designed. To decouple different channels of the multivariable system, a robust decoupling control synthesis procedure for multiloop control systems has been presented [25]. An adaptive PID speed control scheme for permanent magnet synchronous motor (PMSM) drives is proposed [26].…”

Design of robust pre‐compensators for decoupling polytopic linear systems

“…7 More recently, dynamic pre-compensators have emerged as a more attractive alternative. 6,7,9,14 In References 6 and 7, the design of dynamic pre-compensators is based on a quadratic programming optimization in the frequency domain, but no uncertainties are allowed. Reference 9 extends the results presented in Reference 8 to propose an LMI procedure to design dynamic pre-compensators for systems subject to unstructured uncertainties.…”

“…Considering model uncertainties in designing robust pre-compensators to obtain diagonal dominance has been done conservatively in some works. 9,[13][14][15][16][17] Unstructured uncertainties in the model are considered in Reference 9, considering constraints on the singular values of the open-loop plant, and in Reference 13, where diagonal static pre-compensators are designed using the bounds on the row and in the  ∞ norm of the uncertainty. In Reference 15, the robust decoupling problem is performed using a state feedback design approach, resulting in a diagonally dominant closed-loop plant.…”

“…However, the performance in achieving diagonal dominance may be poor in frequency since it depends highly on the plant's frequency response 7 . More recently, dynamic pre‐compensators have emerged as a more attractive alternative 6,7,9,14 . In References 6 and 7, the design of dynamic pre‐compensators is based on a quadratic programming optimization in the frequency domain, but no uncertainties are allowed.…”

“…However, the design is not oriented to reduce the diagonal dominance in medium or low frequency for strictly proper systems. A robust decoupling control synthesis is presented in Reference 14, but it results in a non‐convex optimization problem.…”